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Abstract:

A thermoelectric generator of a vehicle converts thermal energy of
exhaust gas of an engine into electric energy by using a thermoelectric
phenomenon, and may include: a high-temperature part heated by exchange
heat and a plurality of pairs of heat transfer plates mounted on an outer
peripheral surface of an exhaust pipe at a predetermined interval; pairs
of thermoelectric modules acquired by bonding a P-type semiconductor and
an N-type semiconductor, interposed between the pairs of heat transfer
plates to generate electricity, and electrically connected to each other;
and a low-temperature part interposed between the pairs of thermoelectric
modules and cooling inner surfaces of the pairs of thermoelectric
modules. The plurality of thermoelectric modules generates electricity by
a difference in temperature between heated outer surfaces and cooled
inner surfaces. Thermoelectric efficiency is improved and a small-sized
thermoelectric generator of a vehicle may be implemented.

Claims:

1. A thermoelectric generator of a vehicle, comprising: a
high-temperature part including an exhaust pipe heated by exchange heat
with exhaust gas while high-temperature exhaust gas passes therein and a
plurality of pairs of heat transfer plates mounted on an outer peripheral
surface of the exhaust pipe at a predetermined interval and heated by the
exhaust pipe; a plurality of pairs of thermoelectric modules acquired by
bonding a P-type semiconductor and an N-type semiconductor, interposed
between the plurality of pairs of heat transfer plates to generate
electricity by using a thermoelectric phenomenon, and electrically
connected to each other; and a low-temperature part interposed between
the plurality of pairs of thermoelectric modules and cooling inner
surfaces of the plurality of pairs of thermoelectric modules by cooling
water that flows therein, wherein the plurality of thermoelectric modules
generates electricity by using the thermoelectric phenomenon by a
difference in temperature between outer surfaces heated by the heat
transfer plate and inner surfaces cooled by the low-temperature part.

2. The thermoelectric generator of a vehicle of claim 1, wherein: the
low-temperature part includes, a plurality of circular cooling water
passages interposed between the plurality of pairs of thermoelectric
modules, in which the cooling water flows therein, and having a cooling
water inlet through which the cooling water is introduced, which is
formed at one side of one surface and a cooling water outlet through
which the cooling water is discharged, which is formed at one side of the
other surface; and a cooling water passage connecting unit connecting the
cooling water inlet of an adjacent cooling water passage and the cooling
water outlet of the other adjacent cooling water passage among the
plurality of cooling water passages.

3. The thermoelectric generator of a vehicle of claim 2, wherein: the
cooling water passage connecting unit includes, a hose mounted on outer
peripheral surfaces of the cooling water inlet and the cooling water
outlet; and a clamp pressing the hose.

4. The thermoelectric generator of a vehicle of claim 2, wherein the
cooling water passage connecting unit is acquired by welding the cooling
water inlet of one adjacent cooling water passage and the cooling water
outlet of the other one adjacent cooling water passage.

5. The thermoelectric generator of a vehicle of claim 2, wherein: the
cooling water passage connecting unit includes, a left-handed screw
formed at the cooling water inlet of one adjacent cooling water passage;
a right-handed screw formed at the cooling water outlet of the other one
adjacent cooling water passage; and a connection nut connecting the
cooling water inlet and the cooling water outlet by screw-coupling.

6. The thermoelectric generator of a vehicle of claim 2, wherein the
cooling water passage connecting unit includes a press sealing interposed
between the cooling water outlet of the other one adjacent cooling water
passage having a larger diameter than the cooling water inlet of one
adjacent cooling water passage.

7. The thermoelectric generator of a vehicle of claim 2, wherein the
cooling water passage connecting unit includes a fitting union connecting
the cooling water inlet of one adjacent cooling water passage and the
cooling water outlet of the other one adjacent cooling water passage.

Description:

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] The present application claims priority of Korean Patent
Application Number 10-2011-141320 filed Dec. 23, 2011, the entire
contents of which application is incorporated herein for all purposes by
this reference.

BACKGROUND OF INVENTION

[0002] 1. Field of Invention

[0003] The present invention relates to a thermoelectric generator, and
more particularly, to a thermoelectric generator of a vehicle that
generates power by using heat of exhaust gas of the vehicle.

[0004] 2. Description of Related Art

[0005] A thermoelectric element refers to an element using a
thermoelectric phenomenon in which a difference in temperature between
both ends of the element is converted into electricity to convert thermal
energy into electric energy or the difference in temperature between both
ends of the element is caused by making electricity flow on the element
to convert the electric energy into the thermal energy. The
thermoelectric element is used in a small-scale cooling device, a
small-scale heating device, or a small-scale power generating device.

[0006] The thermoelectric element used in the small-scale power generating
device is called a thermoelectric generating device or a thermoelectric
generator. The thermoelectric generator is primarily used in a power
supply device of a radio communicator, a power supply device of a
spaceship, a power supply device of a nuclear-powered submarine, and a
thermoelectric generator installed in an exhaust system of a vehicle.

[0007] FIG. 1 is a cross-sectional view illustrating a thermoelectric
generator of a vehicle.

[0008] As illustrated in the figure, a thermoelectric generator 10
installed in the exhaust system of the vehicle includes a hexagonal
exhaust heat recovering device 40 through which high-temperature exhaust
gas passes, a cooling device 30 installed outside the exhaust heat
recovering device 40, through which cooling water passes therein, and a
plurality of thermoelectric modules 20 generating electricity by a
difference in temperature between both ends by contacting the outside of
the exhaust heat recovering device 40 and the inside of the cooling
device 30.

[0009] The thermal energy is transferred to the thermoelectric module 20
while the high-temperature exhaust gas flows in the exhaust heat
recovering device 40. A cooling pipe 32 in which the cooling water flows
is formed in the cooling device 30 to increase a difference in
temperature between the inside of the thermoelectric module 20 contacting
the exhaust heat recovering device 40 and the outside of the
thermoelectric module 20 contacting the cooling device 30. As such,
efficiency of the thermoelectric generator installed in the exhaust
system of the vehicle is increased by increasing the difference in
temperature between the inside and the outside of the thermoelectric
module 20.

[0010] The information disclosed in this Background section is only for
enhancement of understanding of the general background of the invention
and should not be taken as an acknowledgement or any form of suggestion
that this information forms the prior art already known to a person
skilled in the art.

SUMMARY OF INVENTION

[0011] In order to produce a lot of electricity in a thermoelectric
generator, that is, in order to increase thermoelectric generation
efficiency, thermal energy of exhaust gas needs to be efficiently
transferred to the thermoelectric module. However, in the thermoelectric
generator of the vehicle in the related art, since the thermal energy of
the exhaust gas is not sufficiently transferred to a high-temperature
part, a recovery ability of the thermal energy of the exhaust gas
deteriorates, and as a result, thermoelectric efficiency of the
thermoelectric generator deteriorates.

[0012] Further, the thermoelectric generator of the vehicle in the related
art is low in thermoelectric generation efficiency compared to a size
thereof because a heat exchange dimension is small, and thus a heat
transfer rate is low, even though the cooling device 30 occupies a large
dimension.

[0013] Accordingly, the present invention attempts to solve the problems
of the related art and provides a thermoelectric generator of a vehicle
which is small and has improved thermoelectric generation efficiency.

[0014] Various aspects of the present invention provide for a
thermoelectric generator of a vehicle including: a high-temperature part
including an exhaust pipe heated by exchange heat with exhaust gas while
high-temperature exhaust gas passes therein and a plurality of pairs of
heat transfer plates mounted on an outer peripheral surface of the
exhaust pipe at a predetermined interval and heated by the exhaust pipe;
a plurality of pairs of thermoelectric modules acquired by bonding a
P-type semiconductor and an N-type semiconductor, interposed between the
plurality of pairs of heat transfer plates to generate electricity by
using a thermoelectric phenomenon, and electrically connected to each
other; and a low-temperature part interposed between the plurality of
pairs of thermoelectric modules and cooling inner surfaces of the
plurality of pairs of thermoelectric modules by cooling water that flows
therein, and the plurality of thermoelectric modules generates
electricity by using the thermoelectric phenomenon by a difference in
temperature between outer surfaces heated by the heat transfer plate and
inner surfaces cooled by the low-temperature part.

[0015] The low-temperature part may include: a plurality of circular
cooling water passages interposed between the plurality of pairs of
thermoelectric modules, in which the cooling water flows therein, and
having a cooling water inlet through which the cooling water is
introduced, which is formed at one side of one surface and a cooling
water outlet through which the cooling water is discharged, which is
formed at one side of the other surface; and a cooling water passage
connecting unit connecting the cooling water inlet of an adjacent cooling
water passage and the cooling water outlet of the other adjacent cooling
water passage among the plurality of cooling water passages.

[0016] The cooling water passage connecting unit may include: a hose
mounted on outer peripheral surfaces of the cooling water inlet and the
cooling water outlet; and a clamp pressing the hose.

[0017] The cooling water passage connecting unit may be acquired by
welding the cooling water inlet of one adjacent cooling water passage and
the cooling water outlet of the other one adjacent cooling water passage.

[0018] The cooling water passage connecting unit may include: a
left-handed screw formed at the cooling water inlet of one adjacent
cooling water passage; a right-handed screw formed at the cooling water
outlet of the other one adjacent cooling water passage; and a connection
nut connecting the cooling water inlet and the cooling water outlet by
screw-coupling.

[0019] The cooling water passage connecting unit may include a press
sealing interposed between the cooling water outlet of the other one
adjacent cooling water passage having a larger diameter than the cooling
water inlet of one adjacent cooling water passage.

[0020] The cooling water passage connecting unit may include a fitting
union connecting the cooling water inlet of one adjacent cooling water
passage and the cooling water outlet of the other one adjacent cooling
water passage.

[0021] According to the thermoelectric generator of the vehicle of the
present invention, even though a dimension of the exhaust gas contacting
the thermoelectric module is large, the overall size of the
thermoelectric generator is small.

[0022] Since a structure is simple and the number of parts is small, a
manufacturing cost is reduced and productivity is improved.

[0023] The size of the thermoelectric generator of the vehicle of the
present invention is small, and as a result, the thermoelectric generator
is easily mounted on a vehicle package and can be applied to various
vehicles.

[0024] A heat-exchange mesh may be installed between the high-temperature
part and the thermoelectric module to increase the contact dimension with
the exhaust gas, and as a result, the thermal energy of the exhaust gas
is more efficiently transferred to the thermoelectric module and noise of
the exhaust gas passing through the thermoelectric module is also
reduced.

[0025] The methods and apparatuses of the present invention have other
features and advantages which will be apparent from or are set forth in
more detail in the accompanying drawings, which are incorporated herein,
and the following Detailed Description, which together serve to explain
certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] FIG. 1 is a cross-sectional view illustrating a thermoelectric
generator of a vehicle in the related art.

[0027] FIG. 2 is a perspective view illustrating an exemplary
thermoelectric generator of a vehicle according to the present invention.

[0028] FIG. 3 is an exploded perspective view of a high-temperature part,
a thermoelectric module, and a low-temperature part of an exemplary
thermoelectric generator of the vehicle according to the present
invention.

[0029] FIG. 4 is a cross-sectional view taken along line A-A' of FIG. 2
and illustrates a state in which the high-temperature part, the
thermoelectric module, and the low-temperature part are coupled.

[0030] FIG. 5 is a cross-sectional view taken along line A-A' of FIG. 2
and illustrates the flow of cooling water that flows in the
low-temperature part.

[0031] FIG. 6 is a cross-sectional view taken along line B-B' of FIG. 2.

[0032] FIGS. 7A, 7B, 7C, 7D and 7E are cross-sectional views illustrating
various examples of a cooling water passage connecting unit of an
exemplary thermoelectric generator according to the present invention.

DETAILED DESCRIPTION

[0033] Reference will now be made in detail to various embodiments of the
present invention(s), examples of which are illustrated in the
accompanying drawings and described below. While the invention(s) will be
described in conjunction with exemplary embodiments, it will be
understood that present description is not intended to limit the
invention(s) to those exemplary embodiments. On the contrary, the
invention(s) is/are intended to cover not only the exemplary embodiments,
but also various alternatives, modifications, equivalents and other
embodiments, which may be included within the spirit and scope of the
invention as defined by the appended claims.

[0034] FIG. 2 is a perspective view illustrating a thermoelectric
generator of a vehicle according to various embodiments of the present
invention. FIG. 3 is an exploded perspective view of a high-temperature
part, a thermoelectric module, and a low-temperature part of the
thermoelectric generator of the vehicle according to various embodiments
of the present invention. FIG. 4 is a cross-sectional view taken along
line A-A' of FIG. 2 and illustrates a state in which the high-temperature
part, the thermoelectric module, and the low-temperature part are
coupled. FIG. 5 is a cross-sectional view taken along line A-A' of FIG. 2
and illustrates the flow of cooling water that flows in the
low-temperature part. FIG. 6 is a cross-sectional view taken along line
B-B' of FIG. 2. FIGS. 7A, 7B, 7C, 7D and 7E are cross-sectional view
illustrating various examples of a cooling water passage connecting unit
of the thermoelectric generator according to various embodiments of the
present invention.

[0035] As illustrated in the figure, a thermoelectric generator 100 of a
vehicle according to various embodiments of the present invention
includes a high-temperature part 110 heated by exchanging heat with
high-temperature exhaust gas discharged from an engine, a low-temperature
part 120 in which cooling water circulated by a cooling system of the
engine flows, and which is installed outside the high-temperature part
110, and a thermoelectric module 130 interposed between the
high-temperature part 110 and the low-temperature part 120 to generate
electricity by using a thermoelectric phenomenon by a difference in
temperature between the high-temperature part 110 and the low-temperature
part 120.

[0036] The high-temperature part 110 includes an exhaust pipe 112 heated
while the high-temperature exhaust gas passes therein and a plurality of
pairs of donut-shaped heat transfer plates 114 installed on an outer
peripheral surface of the exhaust pipe at a predetermined interval.

[0037] Each of the heat transfer plates 114 extends on an inner peripheral
surface in a longitudinal direction and includes a flange 115 contacting
the outer peripheral surface of the exhaust pipe 112 and an opening
portion 113 formed at one side, as illustrated in FIG. 3. The flange 115
transfers thermal energy of exhaust gas to the heat transfer plate 114
through the exhaust pipe 112.

[0038] The exhaust pipe 112 has a hollow cylindrical shape and is heated
by the high-temperature exhaust gas which flows therein. The exhaust pipe
112 heated as above heats the heat transfer plates 114 installed on the
outer peripheral surface thereof. A bypass pipe 117 where the exhaust gas
is bypassed is installed in the exhaust pipe 112. A bypass valve 116 that
opens/closes a terminal of the bypass pipe 117 is mounted on the terminal
of the bypass pipe 117 in order to bypass the exhaust gas according to a
load of the engine. The bypass valve 116 is elastically supported on the
bypass pipe 117 by a spring 118. A plurality of exhaust holes where the
exhaust gas flows is formed in the upstream of the bypass pipe 117 when
the bypass valve 116 is closed.

[0039] A heat-exchange mesh 111 is interposed between the outer peripheral
surface of the bypass pipe 117 and the inner peripheral surface of the
exhaust pipe 112. The heat-exchange mesh 111 exchanges heat with the
high-temperature exhaust gas to absorb the thermal energy of the exhaust
gas and transfer the absorbed heat energy to the exhaust pipe 112. That
is, the thermal energy of the exhaust gas is efficiently transferred to
the exhaust pipe 112 by the heat-exchange mesh 111.

[0040] When the vehicle is driven at a high speed, that is, when the load
of the engine is increased, the exhaust pipe may be overheated. In order
to prevent the overheat of the exhaust pipe, when the engine is in a high
load, the bypass valve 116 is opened and most of the high-temperature
exhaust gas is exhausted through the bypass pipe 117, and as a result,
the amount of exhaust gas that flows between the bypass pipe 117 and the
exhaust pipe 112 is controlled.

[0041] The low-temperature part 120 is positioned between the plurality of
pairs of heat transfer plates 114 of the high-temperature part 110. The
low-temperature part 120 includes a plurality of circular cooling water
passages 122 interposed between the plurality of pairs of heat transfer
plates 114 and a plurality of cooling water passage connecting units 124
alternately connecting the plurality of circular cooling water passages
122 at every 180°.

[0042] As illustrated in FIG. 3, each of the plurality of cooling water
passages 122 includes a cooling water inlet 121 formed at one surface and
one side, through which cooling water circulated by a cooling system of
the engine is introduced and a cooling water outlet 123 formed in a
diagonal direction at an opposite surface to the cooling water inlet 121,
through which the cooling water is discharged. The plurality of cooling
water passages 122 is connected to each other in such a manner that the
cooling water inlet 121 of one cooling water passage 122 and the cooling
water outlet 123 of the other one cooling water passage 122 are connected
to each other in a longitudinal direction by using the cooling water
passage connecting unit 124. That is, three cooling water passages 122
adjacent to each other are connected to each other by the cooling water
passage connecting unit 124 in a state in which the cooling water outlets
123 and the cooling water inlets 121 of two cooling water passages 122
adjacent to each other are first positioned in the same direction.
Another cooling water passage 122 which has not yet been connected is
connected by the cooling water passage connecting unit 124 with the
corresponding cooling water passage 122 rotated at 180° from the
cooling water inlet 121 and the cooling water outlet 123 of the cooling
water passage 122 which has already been connected, that is, at an
opposite side to a center line of the cooling water passage 122. The
cooling water passages 122 connected as above are illustrated in FIGS. 4
and 5.

[0043] As described above, when the cooling water passages 122 are
connected, the cooling water flows in zigzag according to the center line
of the exhaust pipe 112, as illustrated in FIG. 5. A method of connecting
the cooling water inlet 121 and the cooling water outlet 123 is various
and an example thereof is illustrated beginning in FIG.

[0044] 7A.

[0045] FIG. 7(A) illustrates a connection method by a hose. FIG. 6(A)
illustrates a method of inserting the cooling water inlet 121 and the
cooling water outlet 123 of the cooling water passage 122 into the hose
and fixing the outer peripheral surface of the hose with a clamp.

[0046] FIG. 7(B) illustrates a cooling water passage connecting method by
welding. According to this method, the cooling water inlet 121 and the
cooling water outlet 123 have different diameters, and as a result, the
cooling water inlet (alternatively, the cooling water outlet) is inserted
into the cooling water outlet (alternatively, the cooling water inlet)
and both sides are welded to connect two cooling water passages 122.

[0047] FIG. 7(C) illustrates a cooling water passage connection method by
a screw. According to this method, different-direction screws are formed
on the outer peripheral surfaces of the cooling water inlet 121 and the
cooling water outlet 123. For example, when a right-handed screw is
formed on the outer peripheral surface of the cooling water inlet 121, a
left-handed screw is formed on the outer peripheral surface of the
cooling water outlet 123. The outer peripheral surfaces of the cooling
water inlet 121 and the cooling water outlet 123 are coupled to each
other by a nut. Both the left-handed screw and the right-handed screw are
formed at the nuts, and as a result, the cooling water inlet 121 and the
cooling water outlet 123 are coupled to each other by just rotating the
nut.

[0048] FIG. 7(D) illustrates a cooling water passage connection method by
sealing. In this method, the cooling water inlet 121 and the cooling
water outlet 123 have different diameters. The cooling water inlet 121 is
smaller than the cooling water outlet 123 in diameter or otherwise. The
cooling water inlet (alternatively, the cooling water outlet) is inserted
into the cooling water outlet (alternatively, the cooling water inlet)
and one or more press sealing is pressed therebetween to connect the
cooling water inlet and the cooling water outlet to each other.

[0049] Lastly, FIG. 7(E) illustrates a cooling water passage connecting
method by a fitting union. In this case, the cooling water inlet and the
cooling water outlet may be simply connected to each other by using the
fitting union.

[0050] The thermoelectric module 130 is acquired by bonding a P-type
semiconductor and an N-type semiconductor, and is manufactured in a
circular shape, which has an opening portion 132 of which one side is
opened. A pair of thermoelectric modules 130 is attached to both surfaces
of one cooling water passage 122 of the low-temperature part 120 and the
pair of heat transfer plates 114 are positioned on an outer surface
thereof. The plurality of thermoelectric modules 130 is electrically
connected to a battery of the vehicle while the thermoelectric modules
130 are electrically connected to each other.

[0051] Outer surfaces of the plurality of thermoelectric modules 130
contact inner surfaces of the plurality of pairs of heat transfer plates
114. The components are installed as above, and as a result, the outer
surfaces of the thermoelectric modules 130 are heated by the plurality of
heat transfer plates 114 and the outer surfaces are cooled by the
plurality of cooling water passages 122. Therefore, a difference in
temperature occurs between both surfaces of the thermoelectric module 130
and the thermoelectric phenomenon occurs in the plurality of
thermoelectric modules 130 by the difference in temperature to produce
electricity. The produced electricity charges the battery electrically
connected with the plurality of thermoelectric modules 130.

[0052] An operation of the thermoelectric generator 100 of a vehicle
according to various embodiments of the present invention described above
will be described.

[0053] When the engine is driven, the exhaust gas is discharged from the
engine and flows in the exhaust pipe 112 and in this case, the bypass
valve 116 closes the bypass pipe 114. Meanwhile, the cooling water
circulated by the cooling system of the engine is introduced into the
cooling water inlet 121 of the cooling water passage 112 positioned at an
outermost side to circulate in the cooling water inlet 121 and circulates
in the other cooling water passage 122 connected by the cooling water
passage connecting unit 124.

[0054] The exhaust gas exchanges heat with the exhaust pipe 112 while
circulating in the exhaust pipe 112 to heat the exhaust pipe 112. The
heat transfer plate 114 installed on the outer peripheral surface of the
exhaust pipe 112 is heated by the heated exhaust pipe 112 and the thermal
energy of the exhaust gas is transferred to the plurality of
thermoelectric modules 130 by the heated heat transfer plate 114 to heat
the outer surfaces of the plurality of thermoelectric modules 130.

[0055] Meanwhile, the cooling water introduced through the cooling water
inlet 121 circulates in the plurality of cooling water passages 122
connected by the cooling water passage connecting unit 124. Inner
surfaces of the plurality of thermoelectric modules 130 are cooled by the
cooling water that circulates.

[0056] Therefore, a difference in temperature occurs between both surfaces
of the plurality of thermoelectric modules 130 arranged on the outer
peripheral surface of the exhaust pipe 112 at a predetermined interval.
Electricity is generated inside the plurality of thermoelectric modules
130 by the difference in temperature. The electricity produced by the
plurality of thermoelectric modules 130 charges the battery electrically
connected to the plurality of thermoelectric modules 130.

[0057] When the speed of the vehicle is increased, that is, when the load
of the engine is increased, the bypass valve 116 opens the bypass pipe
117 over elastic force of the spring 118. The bypass pipe 117 is opened,
and as a result, most of the exhaust gas is exhausted through the bypass
pipe 117 and the rest thereof circulates between the bypass pipe 117 and
the exhaust pipe 112. The heat-exchange mesh 111 interposed between the
bypass pipe 117 and the exhaust pipe 112 exchanges heat with the exhaust
gas to heat the exhaust pipe 112 and a subsequent operation is similar as
that in the case where the bypass valve 116 is closed. Therefore, a
description thereof will be omitted.

[0058] As such, according to the thermoelectric generator of a vehicle of
the present invention, since the structure thereof is simple and the
number of parts is small, a manufacturing cost is reduced and
productivity is improved. The thermoelectric generator of a vehicle is
easily mounted on the vehicle and may be applied to various vehicles.

[0059] For convenience in explanation and accurate definition in the
appended claims, the terms left or right, and etc. are used to describe
features of the exemplary embodiments with reference to the positions of
such features as displayed in the figures.

[0060] The foregoing descriptions of specific exemplary embodiments of the
present invention have been presented for purposes of illustration and
description. They are not intended to be exhaustive or to limit the
invention to the precise forms disclosed, and obviously many
modifications and variations are possible in light of the above
teachings. The exemplary embodiments were chosen and described in order
to explain certain principles of the invention and their practical
application, to thereby enable others skilled in the art to make and
utilize various exemplary embodiments of the present invention, as well
as various alternatives and modifications thereof. It is intended that
the scope of the invention be defined by the Claims appended hereto and
their equivalents.

Patent applications by Ho-Chan An, Hwasung-Shi KR

Patent applications by Hyundai Motor Company

Patent applications by Kia Motors Corporation

Patent applications by Sejong Ind. Co., Ltd.

Patent applications in class Exhaust gas or exhaust system element heated, cooled, or used as a heat source

Patent applications in all subclasses Exhaust gas or exhaust system element heated, cooled, or used as a heat source